Bioinspired Materials: Bio‐inspired Design of Submerged Hydrogel‐Actuated Polymer Microstructures Operating in Response to pH (Adv. Mater. 12/2011)

The cover depicts polymer “microfins” embedded in pH-responsive gel and submerged in water. Actuation of the fins driven by volume phase transitions in a pH-responsive hydrogel “muscle” may be able to drive the flow of particles in solution, as proposed on p. 1442 by Joanna Aizenberg and co-workers. The system is designed to provide uniform directional bending actuation over a large area and integrated with electrochemical and microfluidic cells.